[U-Boot] [PATCH resend 5/7] mtd/st_smi: Write to flash in a tight loop

[Stefan Roese]

On 12/06/2012 07:21 AM, Vipin Kumar wrote:
> The write loop is checking for dest_addr alignment with page size. This
> sometimes leads to smi controller coming out of write mode and eventually the
> next write failing with ERF1 being set.
> 
> To avoid this, write to flash in a tight loop and write bytewise to also support
> not word aligned data bytes to be written. Additionally, enable burst mode
> before this loop so that the controller does not deselect the chip if the
> transfer is finished.
> 
> Signed-off-by: Vipin Kumar <vipin.kumar at st.com>
> ---
>  drivers/mtd/st_smi.c | 30 +++++++++++++-----------------
>  1 file changed, 13 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/mtd/st_smi.c b/drivers/mtd/st_smi.c
> index a84802a..998bacb 100644
> --- a/drivers/mtd/st_smi.c
> +++ b/drivers/mtd/st_smi.c
> @@ -368,13 +368,11 @@ static int smi_sector_erase(flash_info_t *info, unsigned int sector)
>   *
>   * Write to SMI flash
>   */
> -static int smi_write(unsigned int *src_addr, unsigned int *dst_addr,
> +static int smi_write(unsigned char *src_addr, unsigned char *dst_addr,
>  		     unsigned int length, ulong bank_addr)
>  {
> -	u8 *src_addr8 = (u8 *)src_addr;
> -	u8 *dst_addr8 = (u8 *)dst_addr;
>  	int banknum;
> -	int i, issue_we;
> +	int issue_we;
>  
>  	switch (bank_addr) {
>  	case SMIBANK0_BASE:
> @@ -400,7 +398,10 @@ static int smi_write(unsigned int *src_addr, unsigned int *dst_addr,
>  	writel(readl(&smicntl->smi_cr1) & ~SW_MODE, &smicntl->smi_cr1);
>  
>  	/* Perform the write command */
> -	for (i = 0; i < length; i += 4) {
> +	while (length) {
> +		int k;
> +		unsigned int wlen = min(SFLASH_PAGE_SIZE, length);
> +
>  		if (issue_we || (((ulong)(dst_addr) % SFLASH_PAGE_SIZE) == 0)) {
>  			issue_we = 0;
>  
> @@ -412,19 +413,14 @@ static int smi_write(unsigned int *src_addr, unsigned int *dst_addr,
>  				return -EIO;
>  		}
>  
> -		if (length < 4) {
> -			int k;
> +		writel(readl(&smicntl->smi_cr1) | WB_MODE, &smicntl->smi_cr1);

Use setbits_le32() please.

> -			/*
> -			 * Handle special case, where length < 4 (redundant env)
> -			 */
> -			for (k = 0; k < length; k++)
> -				*dst_addr8++ = *src_addr8++;
> -		} else {
> -			/* Normal 32bit write */
> +		for (k = 0; k < wlen; k++)
>  			*dst_addr++ = *src_addr++;
> -		}
>  
> +		writel(readl(&smicntl->smi_cr1) & ~WB_MODE, &smicntl->smi_cr1);

clrbits_le32()

Thanks,
Stefan